The following is a gathering of links to each page of this "What-If?" I've done involving Tarble and Goku growing up together on Earth.
I will continue to add more links as I get more of my story finished - with my story mixing the events from the anime, movies and some of the games into a single timeline. I will admit, I am also using some of MasakoX's ideas for this as he was the one who inspired me to do this.
For this story, I took the idea of Tarble - Vegeta's younger brother - been born in Age 733, a year after his brother. While born with a decent power level (between 8500 and 9000), he is labelled 'low class' due to his lack of aggression and natural initiative for fighting.
In this story, however, Tarble's mother convinces King Vegeta to give her second son another chance instead of sending him away immediately - just in case their son is a late bloomer. This gives Tarble four years of development before that fateful day in Age 737 when Lord Frieza turns up to do the deed, with a series of events leading to the young prince been bundled into the same pod as Bardock and Gine's second son, Goku (or to use his Saiyan name, Kakarot)
In this case, Tarble takes it upon himself to act like a big brother to the younger Saiyan - raising him to be as strong as possible during their time on Earth so that if Frieza or other evil forces come knocking, the pair will be able to deal with it as best as possible.
And so, with the following been ideas from me as to what might happen, their adventure together begins...
03. Emperor Pilaf Saga
04. Tournament Saga
05. Red Ribbon Army Saga (Part 01)
06. Red Ribbon Army Saga (Part 02: General Blue)
07. Red Ribbon Army Saga (Part 03: Commander Red)
08. Fortuneteller Baba Saga (Curse of the Blood Rubies and Sleeping Princess in Devil's Castle)
09. Tien Shinhan Saga
10. King Piccolo Saga
11. "Piccolo Junior" Saga
12. Dragon Ball - Dragon Ball Z (Interlude) (Dead Zone)
Dragon Ball Z
13. Saiyan Saga - Part 01 (Raditz)
14. Saiyan Saga - Part 02 (Vegeta)
15. Namek Saga - Part 01 (Interlude) (The World's Strongest and Tree of Might)
16. Namek Saga - Part 02 (Journey to Namek)
17. Namek Saga - Part 03 (Sanjou! Ginyu Tokusentai!)
18. Frieza Saga - Part 01 (All-Out War)
19. Frieza Saga - Part 02 (A Legend Reborn)
20. Frieza/Android Interlude - Part 01 (War of the Worlds)
21. Frieza/Android Interlude - Part 02 (The Shape of Things to Come) (Lord Slug)
22. Android Saga - Part 01 (Revenge of the Red Ribbon Army)
23. Android Saga - Part 02 (Attack of the Androids) (Super Android 13!)
24. Imperfect Cell Saga - Part 01 (The Bio-Android Menace)
Dragon Ball Super
(To Be Added)
The Peaceful Saga (End of Z)
(To Be Added)